How to set ramps on a (very?) restricted controller?

[omena 0]

Hi everyone,

I have recently got an Uhlig U 500T kiln. I have never fired anything before and it gives me a really hard time to understand how to operate this one particularly, because there seems to be no resource or manual on the internet (the only thing that came with it is in German and kind of explaining how to use the controller tho). 

As far as I understood the slowest possible heating is to 500C in 5 hours. My pieces are quite thin and dry so I am hoping this is fine. Still, I am wondering is it really possible that this is the slowest option? 

My plan is for bisque firing my pieces then, to set it to 500C in 5h and then leave the vent open for 1-2 hours (while testing the steam). After the 5 hours, set it to 950C as the end temperature and chose a shorter time maybe 3 or 4 hours. 

Anyone more experienced than me, does this sound alright? 

Thank you very much!

[Babs 1,132]

If the % is energy input ie amount of time power is going to elements then maybe try something like 25 % 2hrs to 200deg C

Then  50%3hrs to 600degC

100% 4hrs to 1000deg C

I'm saying this as bisque creep up low in the firung and speed it up in each ramp thereafter

960 pretty low bisque imo

Have you a pyrometer or cones so you can find out what is going on in there ?

Cones dotted around the shelves.  cone 06 about 1000deg 

I would put cones  05, 06, 07, 08  

You could get that translated pretty easily in Mr Google.

[Min 3,025]

Contact info for Uhlig, look to be for enameling or silver clay. https://laborofen.com/de/Uhlig-Oefen  I'ld send them an email with a photo of what you have and ask them.

[omena 0]

Thank you Babs and Min!

I was planning the end around 960C as earlier I went to a studio that offered firing service and they fired my pieces from the same clay, same thickness at this temperature (then glazed around 1100c) and they turned out fine.  As far as I understood the German (I do speak a little), % relates to the time, as the example says: 4,5 hours with 30% makes it 1,5h. 

And the lowest temperature I can set is 500C. I plan to buy cones and need to replace the ceramic cover of the thermometer rod (?) anyways, already contacted the company about that. 

 

[Babs 1,132]

Your pyrometer  will work without a cover as long as the two wires are soldered at the end. The tube is just a protective sheath. If dollars a prob that could wait.

Leave the bungs out for first part of a bisque firing.

Let us know how you go.

1.5hrs to 500degC too fast for a starting ramp for a bisque imo

The example given states what you wrote..you'd dial in 100%????

So your time to reach 500deg would be 5 hours.

Seems odd   reverse of what is logical???

Just mulling here.

Edited July 18, 2019 by Babs
additional info

[Chilly 842]

22 hours ago, Babs said:

If the % is energy input ie amount of time power is going to elements then maybe try something like 25 % 2hrs to 200deg C

Then  50%3hrs to 600degC

100% 4hrs to 1000deg C

I think @Babssums it up very nicely.

I too am convinced % = energy, or the amount of time that the elements are switched on for.

500C might be the lowest setting, but those dials usually have a wide fluctuation of accuracy.

With most kilns and controllers, the settings are the maximum you would want the kiln to heat at.  BUT, most kilns won't be able to heat as fast as the settings would allow.

So, if you set 100% for 1 hour to 1200C, your kiln would struggle to meet those demands.

 

Try @Babssuggestion, and see how it goes.